ASTM F2491-05

Standard Guide for Determining Load Ratios for Technical Rescue Systems and Equipment

SCOPE
1.1 This guide covers the general concept of determining load ratios for technical rescue equipment and systems.
1.2 The values stated in SI units shall be considered as standard. Values in English units may be included for reference.
1.3 In the event of any conflict between the text of this guide and any references cited, the text of this guide takes preference.
1.4 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Mar-2005
• ICS: 13.220.10 - Fire-fighting
• Technical Committee: F32 - Search and Rescue
• Drafting Committee: F32.01 - Equipment, Testing, and Maintenance

Relations

• Replaced By: ASTM F2491-05(2010)e1 - Standard Guide for Determining Load Ratios for Technical Rescue Systems and Equipment
• Effective Date: 01-Dec-2010

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:F2491–05
Standard Guide for
Determining Load Ratios for Technical Rescue Systems and
Equipment
This standard is issued under the fixed designation F2491; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Significance and Use
1.1 This guide covers the general concept of determining 3.1 This guide may be used to provide a consistent method
load ratios for technical rescue equipment and systems. for determining load ratios for technical rescue equipment and
1.2 The values stated in SI units shall be considered as systems.
standard. Values in English units may be included for refer- 3.2 Use of this guide will help to maintain clearer, more
ence. consistent calculation and reporting of load ratios.
1.3 Intheeventofanyconflictbetweenthetextofthisguide 3.3 It should be acknowledged that, while component load
and any references cited, the text of this guide takes preference. ratios are fairly straightforward to calculate, they are of limited
1.4 This standard may involve hazardous materials, opera- value for estimating system load ratios. System load ratios are
tions, and equipment. This standard does not purport to usually desired for field applications, but are more difficult to
address all of the safety concerns, if any, associated with its calculate accurately.
use. It is the responsibility of the user of this standard to
4. Load Ratio
establish appropriate safety and health practices and deter-
mine the applicability of regulatory limitations prior to use. 4.1 Load ratio refers to the ratio between the breaking
strength of the item and the load that the item is intended to
2. Terminology
suspend.
2.1 Definitions of Terms Specific to This Standard: 4.2 Various load ratios may be used for different reasons for
2.1.1 component—an individual piece of equipment in its a particular piece of equipment.
usable form, but unconnected and unencumbered by other 4.2.1 A manufacturer may or may not have a specified
pieces of equipment in a system. design factor, representing the ratio between the breaking
2.1.2 force multiplying situation—a situation where the strength of the product and the working load (that is, the load
rigging causes a force on a component to be greater than that the product is designed to carry on a normal basis).
caused by the load. 4.2.2 Users of equipment may specify a load ratio for
2.1.3 load ratio—ratio between a specified breaking equipment that will help them to maintain system safety factors
strength and an anticipated load. that are acceptable within their own scope.
2.1.4 strength reduction situation—a situation where the 4.2.3 The load ratio specified by an equipment user shall be
rigging of the system causes a component to not perform at its no lower than that specified by the manufacturer, if the
minimum breaking strength.An example would be a carabiner manufacturer specifies this information.
with tri-axial forces. 4.3 Load ratio is applicable only to the component, and does
2.1.5 system—a group of components integrally connected not address how this component affects or is affected by other
for the purpose of accomplishing work. components in a system.
2.1.6 system safety factor—the ratio of the load at which 4.4 Load ratios, when used, should always be determined
something will fail and the load that is planned to be applied to using minimum breaking strength as the foundation (rather
the system at that point. than average or maximum or other)
2.1.7 user—a person, agency, or representative who has
5. System Safety Factor
authority to make safety-related decisions for rescue applica-
5.1 System safety factor refers to the ratio between the
tions as discussed herein.
strength of the calcu
...